Haematological Emergencies

Question 1

What haematological emergencies would be seen on the haematology ward?

Answer 1

• neutropenic sepsis
• pneumonia
• hypercalcaemia & hyperviscosity
• spinal cord compression
• acute kidney failure
• tumour lysis syndrome
• sickle cell crisis
• acute haemolysis
• acute haemorrhage in haemophilia A or B
• new acute leukaemia
• mediastinal mass

Question 2

What is neutropenic sepsis?

how is it defined?

Answer 2

a potentially life-threatening complication of neutropenia (low neutrophil count)

defined by a temperature greater than 38^oC and any symptoms/signs of sepsis in a patient with a neutrophil count of 0.5 x 10⁹ or lower

chemotherapy often causes neutropenia

Question 3

What is meant by hyperviscosity syndrome?

What usually causes it?

Answer 3

increased blood viscosity means that blood is unable to flow freely through arteries

it is usually due to increased circulating serum immunoglobulins

it can lead to arterial blockages

Question 4

Why is spinal cord compression a haematological emergency?

Answer 4

an accumulation of blood (haematoma) may occur in or around the spinal cord

spinal epidural haematoma can compress the spinal cord when blood accumulates in the loose areolar tissue between the vertebrae and the dura of the spinal canal

cancer may have metastasized to the spine (or area around it) and caused compression

Question 5

What is meant by tumour lysis syndrome?

How can this affect the blood?

Answer 5

a condition that occurs when a large number of cancer cells die within a short period and release their contents into the blood

this leads to levels of uric acid, postassium and phosphorous rising faster than the kidneys can remove them

Question 6

What happens in a sickle cell crisis?

Answer 6

sickled red blood cells block small blood vessels that carry blood to the bones

this leads to pain in the back, legs, knees, arms, chest or stomach

this pain can be throbbing, sharp or stabbing

Question 7

What is the most common cause of acute haemolysis?

Answer 7

acute haemolytic transfusion reaction

the reaction is triggered by pre-formed host antibodies destroying donor red blood cells

this occurs due to ABO group incompatibility

Question 8

What is haemolysis?

What condition can result if it is not resolved?

Answer 8

haemolysis is the destruction of red blood cells, leading to the release of haemoglobin into the blood stream

if the RBCs are destroyed faster than they can be replaced, this leads to haemolytic anaemia

Question 9

Why is new acute leukaemia a haematological emergency?

Answer 9

leukaemia is a cancer of white blood cells, classified by the type of WBCs that are affected

acute leukaemia means that the cancer will progress quickly and aggressively

Question 10

Why is a mediastinal mass a haematological emergency?

Answer 10

mediastinal tumours are growths that form in the area of the chest that separates the lungs

the mediastinum is surrounded by the breastbone in front, spine in back and the lungs on each side

the mediastinum contains the heart, aorta, oesophagys, thymus, trachea and lymph nodes

Question 11

What are haematological emergencies which may occur on a general ward?

Answer 11

• pulmonary embolism
• deep venous thrombosis
• transfusion reactions
• heparin induced thrombocytopenia
• immune thrombocytopenia purpura
• disseminated intravascular coagulation
• over anti-coagulated patient
• management of the anti-coagulated patient undergoing acute surgery
• thrombotic thrombocytopenic purpura
• HELLP syndrome

Question 12

What are the 4 different results of transfusion reactions?

Answer 12

• haemolysis
• febrile non-haemolytic
• transfusion related acute lung injury (TRALI)
• massive transfusion

Question 13

What is meant by a febrile non-haemolytic transfusion reaction?

Answer 13

it is defined as a temperature increase of 1^oC above 37^oC occuring during or after the transfusion of blood components

it is associated with fever but not directly with haemolysis

it can be mediated by pre-formed cytokines in the donor plasma as a consequence of white blood cell breakdown

Question 14

What is a transfusion related acute lung injury?

Answer 14

a serious blood transfusion complication characterised by the acute onset of non-cardiogenic pulmonary oedema following transfusion of blood products

Question 15

What is a massive transfusion?

What are the main complications of massive transfusion?

Answer 15

the replacement by transfusion of 10 units of red cells in 24 hours

it is a response to massive and uncontrolled haemorrhage

complications include haemolysis and air embolism

this can lead to the patient presenting with cardiac arrhythmias and cardiac arrest

Question 16

What causes heparin induced thrombocytopenia?

Answer 16

it is caused by antibodies that bind to complexes of heparin and platelet factor 4 (PF4)

this activates platelets and promotes a prothrombotic state

it is more common in unfractionated heparin than with low molecular weight heparin

Question 17

What is immune thrombocytopenic purpura?

What tends to cause it?

Answer 17

a condition which causes the number of platelets in the blood to be reduced

it usually happens when the immune system attacks and destroys platelets

this may be triggered by infection with HIV, hepatitis or H. pylori

Question 18

What happens in disseminated intravascular coagulation?

Answer 18

small blood clots develop throughout the bloodstream, blocking small blood vessels

increased clotting depletes platelets and clotting factors, leading to excessive bleeding

Question 19

What should be done initially in an over anti-coagulated patient?

Answer 19

stop the anticoagulant

correct haemodynamic compromise with IV fluid and red cells

Question 20

What is thrombotic thrombocytopenic purpura?

What are the consequences of this disease?

Answer 20

it is a rare blood disorder characterised by clotting in small blood vessels, resulting in a low platelet count

it leads to low platelet count, low RBC count due to their breakdown and often heart and brain dysfunction

Question 21

What causes thrombotic thrombocytopenic purpura?

Answer 21

a lack of activity in the ADAMTS13 enzyme, which is involved in blood clotting

Question 22

What is meant by HELLP syndrome?

Answer 22

it is a complication of pregnancy that is characterised by:

• haemolysis
• elevated liver enzymes
• low platelet count

it usually begins during the last 3 months of pregnancy or shortly after child birth